http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
class io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise<V> extends io.netty.util.concurrent.DefaultPromise<V>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise
  super_class: io.netty.util.concurrent.DefaultPromise
{
  void <init>(io.netty.util.concurrent.EventExecutor);
    descriptor: (Lio/netty/util/concurrent/EventExecutor;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise this
        start local 1 // io.netty.util.concurrent.EventExecutor executor
         0: .line 143
            aload 0 /* this */
            aload 1 /* executor */
            invokespecial io.netty.util.concurrent.DefaultPromise.<init>:(Lio/netty/util/concurrent/EventExecutor;)V
         1: .line 144
            return
        end local 1 // io.netty.util.concurrent.EventExecutor executor
        end local 0 // io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    2     0      this  Lio/netty/util/concurrent/ImmediateEventExecutor$ImmediatePromise<TV;>;
            0    2     1  executor  Lio/netty/util/concurrent/EventExecutor;
    MethodParameters:
          Name  Flags
      executor  

  protected void checkDeadLock();
    descriptor: ()V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=0, locals=1, args_size=1
        start local 0 // io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise this
         0: .line 149
            return
        end local 0 // io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/util/concurrent/ImmediateEventExecutor$ImmediatePromise<TV;>;
}
Signature: <V:Ljava/lang/Object;>Lio/netty/util/concurrent/DefaultPromise<TV;>;
SourceFile: "ImmediateEventExecutor.java"
NestHost: io.netty.util.concurrent.ImmediateEventExecutor
InnerClasses:
  ImmediatePromise = io.netty.util.concurrent.ImmediateEventExecutor$ImmediatePromise of io.netty.util.concurrent.ImmediateEventExecutor